Dampener for printing presses



Nov. 7, 1939.

E. C. -GREMBECKI DAMPENER FOR PRINTI NG PRESSES Filed July 10, 1937 v ,INVENTQR. Q

lhner 6f Grembegkfl H15 ATTORNEY.

Patented Nov. 7, 1939 UNITED STATES PATENT OFFICE DAMTPENER FOR PRINTING PRESSES tion of Illinois Application July 10, 1937, Serial No. 152,927

22 Claims.

This invention pertains to the printing art and more particularly to improved mechanism for dampening plates to lithographic presses, and is in part a continuation of my co-pending application, Serial No. 98,451, filed August 29, 1936 now matured into Patent No. 2,108,984, dated February 22, 1938.

Among its important objects the invention provides mechanism for depositing a uniform and fine coating of water on the lithographing plate, this mechanism including a housing in which is provided a source of water, a power driven chopper for dividing the water into fine particles, means for controlling the water source and means for directing air into the housing in a manner to carry the finely divided water toward a discharge opening of the housing for deposit on the lithographing plate.

Still more particularly stated, the invention has as one of its objects the provision of a substantially closed housing having an open side in confrontation with the plate cylinder of a lithographic press, a water chamber arranged in the housing at a point substantially remote from the discharge opening so that the atomized water will have a path of considerable distance to traverse before reaching the plate.

A further object is the provision of atomizing means in the form of a series of thin discs mounted in spaced relation along a driven shaft journaled in said water chamber in contact with the water therein and adapted to be rotated at relatively high speed to pick up small quantities of the water and throw the same into space for movement with an air current toward the discharge opening. Yet another object is the provision in a device of the class described of a housing having a water chamber with an upper and lower section, the upper section constituting a reservoir and feeding into the lower section, the lower section providing a form of trough into which a predetermined quantity of water is at all times maintained through an automatic valve connection with the upper reservoir section; and atomizing means in the water chamber and including rotatable disc-like members having lower edge portions disposed in contact with the upper regions of the water in the lower section, tog-ether with means in the lower section preventing the formation of vacuum pockets and whirls therein as a result of the high speed movement of the atomizing members through the body of water.

Yet another object is the provision in a dampening mechanism of the class characterized and having a water chamber and atomizing means therein, of air distributing and injection means in the form of an air chamber provided on a wall of the water chamber and having communication with the latter through a narrow elongated slit extended in a parallel sense with the axis of the atomizing plate assembly.

Other novel aspects of construction will appear as the following specification proceeds in view of the drawing in which:

Fig. 1 is a vertical section through the dampening mechanism viewing the same from the side;

Fig. 2 is an enlarged fragmentary vertical section through the water chamber and viewed along lines 2-2 of Fig. 1;

Fig. 3 is an enlarged fragmentary vertical sectional detail of the water feed means as viewed along lines 33 of Fig. 1;

Fig. 4 is an enlarged fragmentary vertical section showing the float valve structure as viewed along lines 4-4 of Fig. 3;

Fig. 5 represents a vertical longitudinal section of a modified form of housing; while Fig. 6 is a perspective'fragment of a modified form of dampener.

As set forth particularly in my above-mentioned application, I have found that by atomizing Water and driving the atomized particles over an elongated path, and preferably but not necessarily one that includes a gravity component against which the particles must move, that an extremely uniform and finely divided mist of water may be provided for deposit on the plate of a lithographic press or the like. The present application concerns itself more particularly with mechanism for atomizing and distributing the water particles.

In Fig. 1, there is shown in fragmentary section part of a rotatable plate cylinder it such as is commonly found in the present day commercial lithographing presses, and upon which is adapted to be mounted a lithographing plate II in which has been etched some desired pattern or indicia to be printed. As is well known in this art, the ink is made to adhere to the un- 45 etched surface portions of the printing plate, and in order to prevent the ink from entering the etched portions water is distributed over the plate with each printing movement or' revolution of the latter in such manner as to cause the water to enter the etched portions, thus preventing the entrance of ink therein.

Many arrangements and expediencies have been resorted to heretofore in an effort to deposit finely divided water uniformly upon the plate, all

without notable success, and with the result that most commercial installations of the present day have resorted to the use of sponge-like dampening blankets attached to a roller and adapted to retain water and distribute such wa= ter over the plate by rolling contact with the same once during each cycle thereof. There are numerous objections to this method of dampening, most important being the unreliability of the method due to the fact that the blanket absorbs ink and hence cannot uniformly distribute the water, the blankets necessarily being frequently changed and requiring skilled handling and supervision in order to procure even moderately satisfactory results.

The improved dampening mechanism of the present application includes some form of housing I2 providing a confined and elongated path for the movement of water particles; in this instance the housing is of somewhat U shape and includes an upper section I3 and a lower section I4 joined by a constricted bight portion I5. The two sections are of substantially shallow depth and are as wide as the plate cylinder ID, the upper section having an open discharge mouth I6 positioned close to the surface of the cylinder I0 and the plate II thereon.

The lower section of the housing includes a water chamber II having an open tank I8 mounted on its upper surface beneath the upper section I3 of the housing. The bottom of the chamber II forms a trough IS in which a predetermined amount of water is maintained by means including a feed pipe 20 (see also Fig. 3) communicating with the lower region of the tank I8 as at 2I and with a float chamber 22 on the trough I9.

The float chamber 22 may be of any suitable design but as shown in Fig. 4 may desirably comprise a housing having a lower chamber 23 into which the feed pipe 2|] leads and an upper chamber 24 shut off from the lower chamber by means of a plummet valve 25 mounted on an end of a rocker arm 26 extending into the trough I9. A gauge glass 39 indicates the water level in the trough I9. At the inner end of the arm 26 is a float 21 adapted to be lifted by a predetermined amount of water in the trough to seat the valve 25 and shut off the flow of. water from the tank I8.

Atomizing means is provided in the form. of a shaft 28 journaled in bearings 29 mounted at opposite sides of the housing l2. A. plurality of chopper discs 30 are mounted in spaced relation between collars 3| on shaft 28 and suitably clamped, for example by means of end nuts 32, for unitary movement with the shaft 28. The discs 30 should be relatively thin and spaced apart a distance bearing a definite relation to the thickness thereof. In one embodiment I have found that discs having a thickness of inch give excellent results when spaced apart a distance of inch. These dimensions may be varied of course dependent upon the type and size of installation required for one or another type of press, but in general the plates are made as thin as possible with a view toward insuring their rigidity when rotated at high speeds.

Mounted on upstanding spacer legs 33 (Fig. 1) on the bottom of the trough I9 is an anti-vacuum means in the form of an apertured plate or grate 34 disposed as closely as possible below the periphery of the chopper or disc assembly, the purpose of this grate-like member being the prevention of whirls and pockets in the body of the water in the path of the several discs.

The anti-vacuum means further includes a pair of flanking guard plates 35 extended across the water chamber and adjustably attached to the walls of the latter by bolts 36 extended through elongated slots 3'! (Fig. 3) therein and threaded into wall portions of the chamber. Each of the plates 35 has a longitudinal edge portion positioned close to the periphery of the disc assembly on either side of that portion of the latter extended into the water so that the plates 35 subsantially close off the trough l9 from the remainder of the water chamber except for a necessary opening into which a small portion of the disc assembly must extend for contact with the water. The plates 35 and the grate 34 cooperate to prevent throwing water away from the discs and impairing the efiiciency of the atomizing mechanism.

Means for transporting the particles of atomized water toward the discharge opening It includes an air chamber 40 mounted on a wall of the water chamber I1 and having communication through a flared sleeve 4! (Fig. 2) with a source of air under a pressure desirably, but not necessarily, of the order of four pounds per square inch.

The air is distributed in the water chamber through a narrow slit 42 which extends horizontally across the partition between the air chamber 4|] and the water chamber I! at a point off center relative to the shaft 28 of the disc assembly and in a direction away from the trough I9 so that the air strikes the discs in regions of the latter advancing directly toward the bight portion I5 of the housing, this latter arrangement having been found to give very good results and being effective to move the particles of water flowing off from the discs 30 uniformly toward the bight portion I5 where the heavier and irregular particles drop out, so that the uniform particles may be carried as a mist into the upper section I3 and out the discharge opening I6 for deposit on the cylinder II.

In order to shut off the flow of atomized water toward the mouth I6 at regular intervals for use with certain types of press, there is provided an automatic valve in the form of an elongated sleeve-like member 43 having diametrically opposite side wall openings 44 extending parallel With its long axis, the sleeve being mounted at its axial ends upon shaft members 45 journaled in the housing. The sleeve 43 is rotatable to bring the opposite open portions 44 thereof in register with the upper section I3 so that the mist may pass unimpeded toward the opening IS. However, when the sleeve is rotated on its shafts 45, diametrically opposite closed wall portions 46 block the movement of the mist toward the discharge mouth.

Means in the form of a plurality of baffles 48 are extended across the width of the upper section I3, and each mounted for individual vertical sliding movement, make it possible to direct the movement of mist toward the plate II for deposit on certain regions of the latter.

Below the upper section I3 and the baffles 48 as well as the gate or sleeve member 43 thereof, is an inclined drip plate or apron 49 which discharges into the open tank I8, thus providing means for returning condensed and settled water particles for recirculation.

The valve member or sleeve 43 is adapted to be rocked intermittently either by direct drive with the cylinder II] or by other timing mechanism so as to shut off the flow of mist at predetermined intervals as particularly provided for in my aforementioned application. It will be apparent that considerable amounts of water will settle out as a result of impingement against the shutter or valve sleeve 43, as well as the baffles 48, and it is desirable to return such water to the tank 18 for reasons hereinafter to be explained.

In Fig. is shown a modified form of housing having an elongated duct section 55 of a width corresponding to the width of a plate cylinder such as cylinder ID of Fig. l, and having a discharge opening or mouth 5| generally similar to the mouth I6 of the housing l2.

A blocking shutter or valve arrangement 52 similar to the shutter mechanism 43 of Fig. 1 is provided in the duct section 50 and the latter has a downwardly directed elbow or bend 53 which terminates in the upper region of a water chamber 54 having a reservoir 55 mounted on its top portion and communicating through a feed pipe 56 with a lower water trough 51 similar to the trough I9 of Fig. 1. A chopper disc assembly 58 is mounted within the chamber 54 in communication with water in the trough 51 thereof as in the case of the device of Fig. 1. However, it will be observed that a considerable space is left in the upper region 59 of the chamber 54 opposite the juncture of the latter with the elbow or bend 53 of duct 55, and it is into this region 59 that particles of water are flung from the chopper assembly 58.

Mounted on the back wall of the chamber 54 is an air chamber 58 similar to the chamber 40 in I the device of Fig. 1 and similarly provided with an elongated distributing slot 6! positioned in a partition 52 between the chamber 60 and chamber 54 at a level substantially in the middle of the upper enlarged region 59 above the discs 58,so that the initially formed water particles will be picked up and moved toward the elbow 53 as in the case of the device of Fig. l. Heavier particles of water will settle out and be returned to the trough 51 whil the more uniform particles will move upwardly against a gravitational component through the elongated duct portion 50 toward the discharge opening 5|.

The form of housing and atomizing means shown in Fig. 6 includes an elongated duct 64 having a discharge opening 65, a shuter or valve member 66, and an elongated rearward duct section 67 terminating at its right-hand end in an air chamber 68 provided with an elongated distributing slot 69 as in the case of the chambers 40 and 56. In this device, however, the atomizing means is provided in the form of an air pipe disposed below the opening 69 above a water trough H from which project upwardly a plurality of spaced feeder tubes 12. Above each tube 12 is the open end of a jet tube 13 from air pipe 18. This arrangement siphons water from trough H and breaks it into fine particles so as to project a spray of water into the rear duct section Bl ahead of air from the slit 69, the rearward duct section 61 being of a length adequate to provide a relatively long path over which the water particles must move before issuing onto the plate. The flow of air from the slit 69 in conjunction with the plurality of sprays projected, eife'cts a uniform movement of fine water particles toward the plate cylinder.

In the use of this device the water supplied to the tank I8 is preferably acidulated and the tank is preferably left open in the manner shown to assist in bringing the water to room temperature. The humidity and temperature in the press room is closely regulated as is well known. In this simple manner operating irregularities due to unlocked for condensation in the region of the juncture of the housing with the cylinder plate, are avoided; and it is therefore desirable to return'water by means such as the apron 49 to the tank E8 to assist in maintaining a uniform water temperature without the necessity of elaborate temperature control means.

Various equivalent arrangements and constructions may be made by those skilled in the art to achieve the objects of the invention, and such modifications and changes either in form or location are all included within the call of the appended claims.

Having thus described my invention, what I claim as new and desire to protect by Letters Patent is:

1. Dampening mechanism for printing presses and the like and comprising a closed housing having an opening arranged in confrontation with a printing plate, a water chamber in said housing at a point remote from said opening, the bottom of said chamber providingatrough,means for maintaining a determined level of Water in said trough, power driven means in said chamber and in contact with the water in said trough for removing water from said trough and discharging the same into space in said chamber, together with means for directing air into said chamber and past said power driven means toward said opening in the housing.

2. Dampening mechanism for printing presses and the like and comprising a substantially closed housing providing an elongated duct portion having a discharge opening positioned close to the plate cylinder of a printing press, said housing having a water chamber at an extremity thereof remote from said discharge opening, said chamber providing a trough, atomizing means in said chamber and including a plurality of spaced discs mounted for rotation therein, said discs being in contact with the water in said trough and adapted to remove water from the latter and dissipate said water into space within the chamber, means for rotating said discs and means for transporting water particles from said chamber through said elongated duct portion and out said discharge opening, said means including an air pressure device having communication with said water chamber and adapted to direct air into the latter in a direction past said atomizing means and toward said discharge opening.

3. Dampening mechanism for use with printing presses having a plate cylinder, said mechanism including a substantially closed housing providing an elongated duct path and having a discharge opening therefor arranged in confrontation with said plate cylinder, said housing having a water chamber at an extremity of said duct path opposite said discharge opening, said chamber providing a trough portion in its lower region, reservoir means in the form of a tank on said housing and means for automatically feeding water from said tank to said trough to maintain a predetermined level of water in the latter, atomizing means in the form of a plurality of thin discs mounted in spaced relation on shaft means: in said chamber with portions of said disc means disposed in the water in said trough, mechanism for rotating said disc means through the water in said trough, an air chamber formed on a side of said Water chamber and having an elongated slit communicating with said water chamber and extended in a direction substantially parallel with said shaft means for moving air past said disc means toward said discharge opening, and means 75 for supplying air under pressure to said air chamber.

4- Dampening mechanism as characterized in claim 3 and further distinguished by the provision of guard members in said water chamber flanking the portions of said disc means disposed in the water in said trough and substantially closing off the latter from the rest of the water chamber.

5. Dampening mechanism in accordance with claim 3 and further characterized by the provision of plate means in said Water trough closely adjacent the periphery of said disc means for prevention of water whirls.

6. In a dampening mechanism for use with printing presses and of the type having a water chamber with discharge opening therein and mechanism. in said chamber for atomizing water therein, air driving means in the form of an air chamber formed on a wall of said water chamber and having an elongated slit communicating into the latter and extending substantially the Width of said water chamber in a position relative to aid atomizing mechanism so as to move a current of air past the same and toward said discharge opening.

7. Atomizing mechanism for use with printing press dampening apparatus, said mechanism including a water chamber providing a trough in its lower region and a discharge opening in a side wall portion thereof, atomizing means including a driven shaft in said chamber and revoluble water engaging means on said shaft and having eccen= tric portions contacting the water in said trough and adapted when revolved to remove small quantities of water and project the same into space in said chamber in the general direction of said discharge opening, means for revolving said shaft, an air chamber formed on a wall of water chamber opposite said discharge opening, means for delivering air under pressure in said chamber and the latter having communication with the water chamber through open wall portions extended across said water chamber along a line substantially parallel to said shaft in a manner to direct air across said revoluble atomizing means toward said discharge opening, an apertured plate member in said trough and disposed close to said atomizing means, together with shield guards in said chamber above said plate means and arranged on opposite sides of said revoluble atomizing means in the region of the juncture of the latter with the water in said trough.

8. Atomizing mechanism in accordance with claim 'I and further characterized by the provision of a tank mounted on said water chamber at a level above said trough and duct means including a float valve mechanism connecting said tank with said trough and operable to maintain a determined level of water in the trough.

9. Dampening mechanism for printing presses and the like and including a water chamber providing a water trough in the lower region thereof, power driven means for throwing particles of water from said trough into space in said chamber, the latter having a discharge opening, air driving means for moving air in said chamber toward said di charge opening and an elongated duct member having communication at one end with said discharge mouth in said water chamber and having at its opposite end a discharge opening arranged in confrontation with the plate cylinder of a printing press, said duct having an upward bend between said discharge mouth thereof and said discharge opening of the water chamber.

10. Dampening mechanism for use with printing presses and the like having a plate cylinder, said mechanism including a water chamber housing a quantity of water, driven mechanism for projecting particles of water from said quantity into space in said chamber, said water chamber having a discharge opening in an upper region thereof, air means for driving particles of water in said chamber toward said discharge opening, and an elongated duct member communicating at one end with said discharge opening in the water chamber and having a discharge mouth at its opposite end, said duct being extended in a substantially horizontal plane from said water chamber and being offset so as to position said discharge mouth thereof at a higher level than said discharge opening in said Water chamber.

11. Dampening mechanism in accordance with claim 10 and further characterized by the provision 01" a water reservoir mounted on an upper portion of said water chamber, together with duct means connecting said reservoir with the lower region of said water chamber and including automatic valve means for maintaining a determinedlevel of water in said chamber.

12. Dampening mechanism for use with printing machines having a plate cylinder, said mechanism including an elongated and substantially linearly extensive duct having a discharge opening arranged in confrontation with said plate cylinder and an air chamber formed at an end thereof opposite said discharge opening, said air chamber having communication with said duct through a narrow slit extending the width of the duct, together with means for providing a spray of water in said duct and arranged at a point in advance or the movement of air from said slit toward said discharge opening, and means for supplying air under pressure to said air chamber.

13. Atomizing mechanism including a chamber having a discharge opening above the bottom thereof, means for maintaining a determined quantity of water in the bottom of said chamber, means in the form of a plurality of spaced discs mounted on a shaft for rotation in said chamber with edge portions of the disc immersed in the water therein, means for rotating said shaft whereby said discs will project particles of Water in the general direction of said discharge opening, an air chamber formed in a side of said first-mentioned chamber opposite said discharge opening and having communication with the la"- ter through an elongated and substantially narrow slit formed in the wall portions between said chambers and extended in a direction substantially parallel with the long axis of said shaft mounting said discs and ofiset radially therefrom so as to be substantially in alignment with said discharge opening, and means for supplying air under pressure to said air chamber.

14. Atomizing mechanism in accordance with claim 13 and further characterized by the provision of flanking guard plates extended across said first-mentioned chamber with edge portions in close proximity to said discs and substantially closing off said quantity of water therein from the remainder of the chamber,

15. Atomizing mechanism in accordance with claim 13 and further characterized by the provision of an apertured plate mounted in the body of Water in said chamber in close proximity to peripheral .edge portions of said discs at their respective points of maximum immersion in said quantity of water.

16. In a device of the class described, means providing a chamber, means for maintaining a predetermined level of water in said chamber, means providing a passage from said chamber, said forwardly directed passage having a discharge opening for confrontation with a printing device, power-driven rotary means in said chamber and normally in contact with the water therein for projecting relatively minute particles of water forwardly into space in the chamber in the general direction of said discharge opening, and means for forcing air into said chamber at a point on a side of said rotary means opposite said discharge opening and operable to force air past said rotary means to carry particles of water toward said discharge opening.

1'7. Dampening mechanism including a chamber, means providing an elongated passage leading in one general direction from said chamber toward a printing device, means for maintaining a quantity of water in said chamber, power actuated means normally contacting said quantity of water and operable to project small particles of water into said chamber in the general direction of said passage, and means for discharging air into said chamber from points along a horizontal line of substantially the same Width as and positioned oppositely to said passage.

18. In a device of the class described, a chamber arranged to maintain a quantity of water in its lower region and having an opening in an upper region thereof, duct means communicating from said opening and having an upwardly oifset section extending in a substantially horizontal direction and terminating in a discharge opening for confrontation in a printing device, distributing means arranged between said quantity of water and said opening for projecting particles of water upwardly in the general direction of said opening, together with means for forcing air past the upper portions of said distributing means toward said opening whereby to carry water particles upwardly into said duct toward said discharge opening.

19. In a dampening mechanism, means providing a housing having a discharge mouth positioned closely opposite a printing device, means providing a trough in the bottom of said housing remote from said mouth, means providing a reservoir above said trough on said housing, and

automatic mechanism for feeding water from said reservoir to said trough to maintain a predetermined level in the water, together with means for effecting removal and comminution of water from said trough and dispersing the comminuted particles into space in said housing, and means for efiecting movement of the comminuted particles toward said mouth.

20. In a dampener, means providing an elongated duct member having an open discharge end for confrontation with a member to be moistened, means providing a chamber at the opposite end of said duct, means providing a source of finely particulated water in said chamber at the opposite end of the duct, and means for urging water particles in substantially evenly distributed relationship from said chamber through said duct and onto the member to be moistened, said last-mentioned means including a duct member adapted for connection to a source of air under pressure, said duct member having an elongated slit communicating into said chamber substantially opposite said opposite end of the duct and extending in a direction across said duct a distance substantially equal to the width of the duct, air issuing from said slit being efiective to move water particles in evenly distributed relationship as aforesaid.

21. Dampening mechanism for printing presses and the like, comprising a housing having an opening confronting a printing plate, means in said housing spaced from said opening for containing water, power-driven rotatable means normally in contact with said water and operable to atomize the same and project the atomized particles into space in the housing, and means associated with said rotatable means for directing air into said housing and past said power-driven means to carry the atomized water toward and through the opening in the housing for deposit on said printing plate.

22. Dampening mechanism for printing presses and the like, comprising a housing having an opening confronting a printing plate, a trough in said housing for containing water, a powerdriven rotatable member normally extending into contact with the water in said trough and operable to atomize the same, and air directing means associated with said rotatable member to carry the water atomized thereby toward and through said opening for deposit onto said plate.

ELMER C. GREMBECKI. 

